/*  
Copyright Microsoft Corporation

Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy of
the License at 

http://www.apache.org/licenses/LICENSE-2.0 

THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED 
WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE, 
MERCHANTABLITY OR NON-INFRINGEMENT. 

See the Apache 2 License for the specific language governing permissions and
limitations under the License. */

using System.Linq;
using MileageStats.Domain.Contracts.Data;
using MileageStats.Domain.Models;

namespace MileageStats.Domain.Handlers
{
    public class GetFleetSummaryStatistics
    {
        private readonly IVehicleRepository _vehicleRepository;
        private readonly IFillupRepository _fillupRepository;

        public GetFleetSummaryStatistics(IVehicleRepository vehicleRepository, IFillupRepository fillupRepository)
        {
            _vehicleRepository = vehicleRepository;
            _fillupRepository = fillupRepository;
        }

        public virtual FleetStatistics Execute(int userId)
        {
            var vehicles = _vehicleRepository.GetVehicles(userId);
            
            var stats = from vehicle in vehicles
                        let fillups = _fillupRepository.GetFillups(vehicle.VehicleId)
                        where fillups.Any()
                        let statistics = CalculateStatistics.Calculate(fillups, includeFirst: false)
                        select statistics;

            // These statistic calculations are for illustrative purposes only.
            // If you were to build this application for real, you probably want to calculate this
            // data more accurately and cache the results.

            return new FleetStatistics(stats);
        }
    }
}